Posted
by
samzenpus
on Monday September 16, 2013 @12:03PM
from the brighter-and-brighter dept.

Zothecula writes "Researchers at the University of Pennsylvania have found a way to harvest energy from sunlight more efficiently, with the help of so-called plasmonic nanostructures. The new findings suggest that plasmonic components can enhance and direct optical scattering, creating a mechanism that is more efficient than the photoexcitation that drives solar cells. The development could therefore provide a real boost to solar cell efficiency and lead to faster optical communication."

But that's not all the article said; it isn't just more surface area, but with plasmonics tuned so that electrical resistance is lower and the maximum number of electrons can get knocked loose by a photon.

Don't expect a physics class in a magazine article, but for someone not in the field wikipedia will do. I looked up plasmonics before reading the article and it made the article a lot more informative.

I was going to submit an article for slashdot about solar energy and this seems to work just as well. I was wondering if a woman could be the new genius like Nikola Tesla. There is a video on this web site solar energy [moteyenergy.com] that describes a device that converts solar energy directly to electrical energy without any semiconductor materials at all, very cheaply and efficiently and could be manufactured by anybody. It seems correct, but I am really confused because it don't think it could be that simple, but the

I've noticed several such huge leaps in efficiency in solar cells, many claiming as much as 50% increase.Some are probably impossible to manufacture, others are mutually exclusive, but take as a whole if you combined them all you would think we were asymptotically approaching 100% efficiency.

Yet even the best hover under 45% efficiency. [wikimedia.org] While that is nothing to sneeze at, commercially available solar cells (as of 2006) and system technology leads (at best) to system efficiencies between 5 and 19%.

In fact, they never do at all! If you look at the market statistics, you will notice that >80% of the market is crystalline silicon. And while there are different ways to manufacture crystalline silicon solar cells, companies have been extremely reluctant to introduce new technologies. In fact, almost all solar cells today are still made with the same manufacturing process steps as 10 years ago. Conversion efficiencies have improved simply by tweaking these process steps.

For how many decades did it seem like hard drives and CRT displays would never be displaced? They just kept steadily improving the whole time, and no fundamentally different technologies could overtake them - until they did. (Hard drives decreased $/byte by increasing the denominator, whereas PV cells decreased $/watt by decreasing the numerator, does that somehow not count?)

Sure, the vast majority of research comes to nothing. The exceptions are what make it possible for 7 billion people to exist on e

I am certain that it is available now because I have it and not only can you buy it but make it yourself for material cost. I have been studying this and Sadoway at MIT has developed a liquid metal battery that will store charge cheaply and I have developed a method to collect energy cheaply and store it in that battery. I understand that Jan 2014 is when they will be in production and I will have a production device and DIY instructions to collect solar , and wind energy before that. So leave your number

If I had a dollar for every time a uni came up with a new solar cell. The reality is that most of what you can buy is stil monocrystalline silicone, same as 50 years ago. Why is nothing commercialised?

Every one of the inventions is being pulled forward. It is clear you have no idea what's available out there. Thin film is beginning to dominate commercial installation, in fact it's so much better that it's very difficult to even purchase thin films any more because all the production is allocated to commercial installations. Other techniques are out there and being used, the better the cell the more likely it'll be relegated to commercial installation. Most of what's available for retail purchase is the output of older cell lines that are no longer competitive on the commercial side.

Solar is now significantly below $1 a watt and is approaching the point where in commercial installations it's amortized cost is approaching that of coal power. It's already cheaper than nuclear on all fronts.

As far as "significantly below $1 a watt", do you simply mean the solar panels themselves? Not installation and the support electronics too, right?

Because it sure seems a lot more than that.. Plus, I can currently get $2/watt rebate through my municipal power supply.. But at a solar/green event I went to, I use so little electricity that only after mentioning that was it *maybe* worthwhile for me. I will get an electric car, but I have a relatively short commute, so that won't increase my usage by orders

"But at a solar/green event I went to, I use so little electricity that only after mentioning that was it *maybe* worthwhile for me."

This is a very good point. Homes, individually, don't take too much power, so powering each one of them with it's own generator (solar or otherwise) is redundant and expensive. Maintenance, too, is a pain for the average home owner. So centralizing power generation is great, for the most part. At least until you start factoring in transmission loss. What ideally will happen, and this will take time thanks to the cooperation it requires, is that district power plants will spring up. That a commercial building can produce so much power that it can sell the rest to local houses. You're starting to see this happen, and in the future, hopefully it will happen more. There's other benefits to this approach as well. Say, for instance, you run a massive server farm. This farm produces a lot of heat, and if you can capture this heat, you could use it to power your building and perhaps other neighboring buildings as well. It's an idea that's catching on in Europe and a few places in the US. So maybe solar power on your home isn't going to become viable, but that doesn't mean solar won't be in your future.

I have 6.2 KW of solar installed. "Maintenance" is spraying the panels with a hose when they get dirty, which is basically never. The occasional rain shower takes of it. My cost was $3.85 a watt, installed (panels, inverters, permits, installation, engineering, labor, everything). My payback, if electricity rates remain flat, is less than 10 years. If rates go up (as they have every year since I started buying electricity), it's sooner.

The real problem I have is that from a purely economical standpoint, it still doesn't make sense. A relatively safe investment will net you 3-5% per year. If you shop around and you can even find investment options that practically guarantee that rate of return. Your $24000 investment is worth ~$100 per month in interest, more over the long term as compound interest starts to kick in. This seriously undermines a purely economics based argument.

All your assumptions assume power prices remain fixed. As he noted his payoff time is 10 years worst case. After those 10 years he has a guaranteed 15 years of warranty on the panels. Actual lifetime is unknown and in fact could be 50 years. Yes the early ROI is low but once you factor in guaranteed and non-guaranteed life the ROI is excellent.

My argument isn't with his numbers, it's with the use of payoff time in general as a measure if an investment is economically viable. It ignores the fact that money tomorrow is worth less than money today. I guess you can argue that's an assumption, but it's an assumption that every economist, investor, bank, lender, borrower, and policy maker in the world agrees is a valid one. Using payoff time is bogus because eventually the value of the payoff is a fraction the value put in at the beginning. If you

I know exactly what you are saying. Are you listening to what I'm saying? Assuming the numbers your using are correct and the payout time calculated as 10 years is accurate, you have a 22k investment that's returned in 10, doubled in 20 and another 50% by the 25 year life (assuming no increase in power rates). So a 22k investment today in 25 years returns 55K in 25 years, but that's assuming power rates remain fixed. It would not be illogical to assume power rates continue the trend of the last 20 years and

The only downside of the Powercube is that the fuel it uses, ammonia, is also one of the primary chemicals used for making meth, so buying ammonia in the quantities required to use it puts someone on a lot of lists.

Solar will not replace the power plant, but it does come into handy during the peak times. What would be a breakthrough would be having research done for a storage medium for solar energy, be it batteries or being able to effectively make/store/use hydrogen.

Homes, individually, don't take too much power, so powering each one of them with it's own generator (solar or otherwise) is redundant and expensive

perhaps that's true if you try to power the whole of a modern house, but i can see the advantages of every house having survival level power production (of whatever kind) for the house if the grid goes offline, perhaps even local communitys meshing their individual production together to support vital local services - all at 'barely keep it going' levels of cou

>Every one of the inventions is being pulled forward. It is clear you have no idea what's available out there. Thin film is beginning to dominate commercial installation, >in fact it's so much better that it's very difficult to even purchase thin films any more because all the production is allocated to commercial installations. Other

Bullshit. Most thin film technologies are DOA. There are two technologies that seem to suceed in the market: CdTe and CIGS. However, due to their low conversion efficienc

Because it turns out you can get more bang for your buck by improving the manufacturing of silicon cells than you can get by launching the alternatives that have been tried so far. Monocrystalline silicone is still king when it comes to conversion efficiency and they're no longer particularly expensive, so way go for second or third best?

Also, it's better to go for higher-efficiency cells whenever you're using some kind of concentrator since the cost of the cell becomes less relevant and a better cell will give you more output power per area of the concentrator.

If I had a dollar for every time a uni came up with a new solar cell. The reality is that most of what you can buy is stil monocrystalline silicone, same as 50 years ago. Why is nothing commercialised?

I think could be related to the types of discoveries. Discovery X gives a 10% increase in efficiency, then discovery Y gives a 8% increase, however discovery X is not compatible with discovery Y, so they both can't be used together. Also discovery X will cost 10x as much as discovery Y, so we'll have to go with Y.

I've seen some panels that use monocrystalline silicon, then areas of polycrystalline because one is better for sun, one for shade. I've also been seeing polycrystalline panels getting about as much efficiency as the single crystals.

It takes a bit for stuff to go from lab to market. Part of it is testing because solar installations are usually thought of as very long term investments, amortized in the terms of 5, 10, or 20 year increments. So, solar makers tend to be fairly conservative on what they put

While this all great Science, actually solar panels are already cheap enough in many parts of the world. Certainly they are in Australia since we have no tariffs on imported Chinese panels. What is really needed for greater market penetration is cheap storage. It would be great to have a around ~20 KWHr of storage for ~$2000 - $4000. Said storage needs to be stable over around 7000 cycles (20 years of operation) and provide of the order of 4 KW of power on demand. With this in place residential PV systems could provide over 20% of demand in many parts of the world.

I can think of a few reasons:1) This doesn't scale. If we want solar to catch on a massive scale, we need a way to either store it, or a way for a night/cloudy/rainy power source to fill in the gaps2) A lot of places where solar would be really useful doesn't have grid access to begin with. Many third world areas (IE: large portions of Africa) come to mind, but there's plenty of other places - the US has large swaths of nothingness that could benefit from solar power but don't have grid connections.3) Portable applications, in which in would be impractical to run a temporary grid connection to it, would do great with some energy storage.

1. How does it not scale? We can use other sources already used to load balance, like natural gas plants.2. Those places don't have the money for it anyway.3. Use solar during day, genset at night. Still cheaper than storage.

1. The idea is to reduce non-renewable sources in favor of renewable sources. The biggest issue facing this in the long run is the need to store the energy as most non-renewable sources are not continuously reliable (wind) or are cyclic (solar, some hydro). Saying you can load balance with a non-renewable resource is a short term solution.

2. Solar is getting pretty cheap, and a lot of places are using it to some degree already. It's not unheard of for poor African villages to use solar to recharge car batteries each day. It's the storage that's the weak link in cases like these moreso than the solar generation.

3. Generators get expensive fast once you consider the indirect costs such as transportation. Also, see 1. Most solutions not involving some kind of energy storage are short term solutions (within the lifetime of people already born).

Why would you want to do that?Why spend a bunch on batteries when the grid is already there? Storing your locally generated power is only worth it if the price to buy power vs the price you sell it at are very far apart.

Or if you have no interest in being connected to the grid and beholden to the power company which can decide to change the rates.

Cottages, remote locations, the developing world... these are all places where there may not be a grid, or where it may not be practical to connect to it.

Why should you even need to involve the utility in this if what you're looking for is a 100% off-grid solution? They're just middlemen and don't bring anything to the table except a place to store your energy... if you could d

You cannot run a house worth of power over an extension cord. Odds are your power system would not survive any better than the grid. I would wager you would be against inspection and regulation as well, but more than happy to have the fire dept rescue you when your uninspected crap burns.

Trains are inflexible, they are not unreliable. I know farmers that live in the city, does that blow your

In some parts of the US, getting a utility company to drop a pole can be $10,000 a mile. For the cost of what it would be for a power pole a few miles out, one could buy themselves a good off-grid system with multiple inverters, good storage batteries, decent MPPT charge controllers, and even single axis trackers.

Solar is becoming one of those "why not" things, rather than "why". Even if one just slaps some panels on the south side of their roof, it will help things, either grid-tied to help with the elec

What an articulate comment. Do you have any other such wisdom to share? Perhaps you can even find a new swear word to try out on us.

By the way, I was not saying the commenter was a nutbag, just the folks who want to live without being reliant on anyone else. It is impossible, unless they can also fab their own solar panels and practice surgery on themselves.

I agree that it's impossible to not be reliant on other people for some services but that doesn'tmean self-sufficiency is a bad goal. You could easily get to the point where you could gomonths or even years without help from the outside world for day to day activities.I also don't think it's a crazy goal. I actually think the opposite is true. The opposite ofself-sufficiency is dependency. When someone loses their job, house, etc... and then has towait for the government to rescue them, companies to cre

Because where I live you sell to the grid at 8 cents per KWHr (which is actually higher than the wholesale price) and buy from the grid at 25 cents per KWHr. Germany is already in trouble because Solar PV has pushed prices down below zero during peak solar production. ie The intermittent nature of solar is already making the technology hit its limits even though the total agregate solar production integrated over a year in Germany is less than 5% (I think). You beat this with local storage.

Then the electric price at that time of day should be very low to buy as well.

I am not suggesting night and day power prices be the same. Only that the power company pay the market price that they charge at that time. Power at night is actually very cheap, in my area at least. This is because of the huge surplus of so many businesses being closed.

Another solution is demand shifting. Homes and businesses can shift their power needs to off-peak periods. Energy sucking appliances can be programmed to only run when the electricity price falls below a threshold. So you load your clothes dryer, or dishwasher, but they don't run until hours later. Your refrigerator and freezer can pre-chill during off peak hours and coast through peak hours. Businesses can receive incentives to move some of their shifts earlier or late

They should pay you MORE than they charge, they're getting power basically for nothing, no fuel, no maintenance. For storage, what about a big underground flywheel? Spin it up with extra renewable power/cheap grid power and sell it back during peak time with a smart inverter. You get lower bills/a credit and they get load balancing as you're providing power locally where it's needed.

FYI they use oil for power in Southern Florida when they get their gas burn forecasts wrong.

They have to tell the pipeline company how much gas they're going to need days ahead of time. The further south the longer ahead of time they have to order their gas. You can't store much gas, oil is more expensive, but it's there.

Both grid-tie systems (selling power to the utility company) and off-grid systems (completely disconnected from mains power) have their benefits and drawbacks.

The nice thing about off-grid power from a properly sized inverter is that you are getting extremely clean power. Essentially this functions similar to a whole-house online (not standby) UPS. This helps prolong the life of virtually any electrical gizmo in the house.

Of course, there are shortcomings. Energy-intensive appliances like HVAC systems, w

We would countries even want tariffs on importing vast amounts of rare Earth minerals below market value? Let China flood the market. At some point in the future, all of us other countries will have huge stock-piles of China minerals in our land-fills.

Cool. Let's stop trying to improve on existing technology then. All those people living in less fortunate countries than Australia and trying to get by on a few dollars a day? Fuck 'em, I can afford the existing tech, that's all that matters. As long as the Chinese don't mind destroying their environment and paying shit wages so I can have cheap imports, I'm happy.

While this all great Science, actually solar panels are already cheap enough in many parts of the world. Certainly they are in Australia since we have no tariffs on imported Chinese panels. What is really needed for greater market penetration is cheap storage. It would be great to have a around ~20 KWHr of storage for ~$2000 - $4000. Said storage needs to be stable over around 7000 cycles (20 years of operation) and provide of the order of 4 KW of power on demand. With this in place residential PV systems could provide over 20% of demand in many parts of the world.

This might be what you've been waiting for, but we still have to actually see it on the commercial market.

http://www.gizmag.com/iron-air-battery/23646/

This cheaper iron electrode is driving costs down significantly, and the researchers are targeting an aggressive $100 per kWh for their batteries. For reference, research firm Lux Research puts the cost of lithium-ion batteries at roughly around $600/kWh and says their cost will decrease quite slowly, dropping below the $400/kWh mark no earlier than in 2020.

But they are nanometres thick as well. Say the structures are ~30nm high and assume that half the surface is covered in gold for the sake of simplicity. Then the volume of gold per m**2 is 15e-9 (m**3) = 0.015 (cm**3)

Density of gold is approx 19.30 g cm**-3 [wikipedia.org] so it needs ~0.3g to make 1 m**2 of material.

Price of gold is around $40/g [goldprice.org] so that's about $12 per metre squared of material.

I had trouble finding reliable estimates of current prices but they seem to be in the range $300-$1500 per square metre.

You'd be surprised at the amount of things precious metals find themselves in. Gold is a great conductor, just like copper and silver (in fact, if it weren't a good conductor, well, it wouldn't be gold), and sometimes it's very useful for certain electrical/optical/electro-optic applications. I can't confirm any of these factually, but I imagine that gold is present in a lot of electronic and optical devices, including microprocessors and certain kinds of sensors, biosensors in particular. The fact that it'

It would be interesting to catalog all of Slashdots 'incredible solar tech invented!' stories from 20010 and see how much of it actually made it into solar panels and exactly how much it actually improved them. Could also do the same for medical "break throughs".